Genotype x environment interaction in Mundo Novo coffee genotypes by non- linear and multiplicative models

The purpose of this study was to evaluate the phenotypic adaptability and stability for yield in coffee genotypes of the cultivar "Mundo Novo" by using the methods TOLER and AMMI, as well as to select genotypes with high productive adaptability in the coffee growing regions of Minas Gerais. The experiments were carried out in Tres Pontas, Campos Altos and Capelinha, Minas Gerais, Brazil, in a randomized complete block design with four repetitions and six plants per plot. The treatments consisted of 33 genotypes of cultivar "Mundo Novo" provided by the coffee plant breeding program of the Instituto Agronomico (IAC). The yield analyses were performed during six harvests, which were grouped in bienniums. Each combination biennium x site was considered an environment totalizing nine environments. Once the genotype x environment interaction was detected by the F test of Snedecor, the stability analysis was done with the adaptation being represented by yield. The methods AMMI and TOLER were similar when classifying the genotypes and environments, and should be used together in coffee breeding programs in order to obtain greater reliability of information, as they are complementary. In this study the stability was associated with low adaptability. The IAC 379-19, IAC 388-6-16 and IAC 403-1 genotypes were unstable with high adaptability. The IAC 2931 and IAC 480 genotypes were classified as desirable due to average stability associated with reasonable yield.